... plating 2.DN15, 1/2", DN20, 3/4 fire sprinkler,sprinkler head,fire nozzle1.ZSTZ-68oC to be installed upward, 2.ZSTX ... its surroundings.size:1.DN 15mm, connect thread R1/2, flow coefficient 80, rated W.P. 1.2MPa2.DN 20mm, connect thread R3 ... /4, flow coefficient 115,rated W.P. 1.2MPa. fire sprinkler ...